Opening device for cartons



June 8, 1954 G. w. MAI 2,680,558 OPENING DEVICE FOR CARTONS Filed Jan.10, 1951 2 Sheets-Sheet 1 INVENTORI GEORGE W MAI ATTORNEYS.

June 8, 1954 s. w. MAI 2,680,558 OPENING DEVICE FOR CARTONS Filed Jan.10, 1951 2 Sheets-Sheet 2 INVENTOR: GEORGE w. MAI

wgwgw ATTORNEYS.

Patented June 8, 1954 UNITED STATE 2,680,558 OPENING DEVICE FOR CARTON SGeorge W. Mai,

St. Loui lord Container Corpo corporation of Maryla s, Mo., assignor toGayration, St. Louis, Mo., a nd Application January 10, 1951, Serial No.205,332 1 Claim. (Cl. 229-5l) marginal portion of the sealing flap isfree of glue so as to provide an unsecured grasping portion or tear tabwhich is torn therefrom thereby breaking the glue joint to open thecarton. One of the principal objections to many of the conventionalsealing flaps of ice cream and other food cartons arises from thefrequent One of the principal objects of the present invention is toprovide a device for cleanly detaching the glued sealing flap of foldingcartons from the underlying wall to which it is attached without peelingportions of the surface of the paperboard in contact with the contentsof the carton.

Another object of the invention is to provide a glued flap for closing acarton which will seecurely seal the package against any accidental orpremature opening and which may be readily released from the glue bondwithout contaminating the contents or the package.

The invention provides means for readily and cleanly detaching a cartonsealing flap connected to a free edge of one panel thereof, said sealingflap being attached to the margin of an adjacent wall panel by alongitudinal strip of glue of less Width than the sealing flap, saidstrip of glue being positioned slits therein, said means comprising alongitudipositioned between the glue strip and the inner longitudinaledge of the sealing flap, said slits being formed of perforationsextending through the liner ply of the inner face of said sealing flapwith the opposite ends of adjacent slits in substantially perpendicularalignment with said longitudinal series of slits.

In a preferred embodiment, the slits extend slit are in substantiallysubstantially parallel to and are positioned between t breaking the gluejoint to open the carton. The size of the perforations may be varied andstill come within the scope of the invention.

comprise two adjacent rows of relatively short evenly spaced slitssubstantially parallel to the fold line of the sealing flap, the slitsof the respective rows being in staggered overlapping relation. In otherforms of the invention, the perforations may take the form of a row ofZ-shaped slits, or a row of straight slits and a row of slits disposedat an angle to the straight slits adjacent to and parallel to the firstmentioned row,

of diagonal slits. Regardless of the shape of the perforations theopposite ends of each staggered adjacent perpendicular alignment withthe fold line of the sealing flap to provide the severed portions ofadjacent staggered slit along a line perpendicw lar to the fold line ofthe sealing flap to insure an invariable clean tear of the liner alongthe end edge of the sealing severed by one of the bottom slits asillustrated in Figures 3 through 6.

The slits are preferably made from the outer or exposed face of thesealing flap, since the slits may be out simultaneously in one operationwith the scoring and die cutting of the carton blank. Obviously, ifdesired they may be cut from the underiace of the blank, but thisusually involves a separate operation.

The invention consists in the parts and in the arrangements andcombinations of parts hereinafter described and claimed. In theaccompanying drawings which form part of this specification and whereinlike numerals refer to like parts wherever they occur:

Fig. 1 is a plan view of a blank for a carton embodying this invention,

Fig. 2 is a perspective view of from the blank shown in Fig. 1 the teartab severed,

the carton folded with a portion of Figs. 3, 4, and 6 are enlargedillustrations of several of the modified forms of the perforations ofthe invention.

Referring now to Figs. 1, 2 and 3 of the drawings in detail, it will beseen that the embodiment of the invention which is illustrated has beenapplied to a s andard one-piece ice cream carton. The blank is shown inFigure 1 wherein a cover panel l, a side or rear wall panel 2, a bottompanel 3, and a side or front wall panel l are defined by scores 5, t, 1,8 and 9 and are provided with end flaps iii, H, i2 and [3 attached tothe ends of wall panels I, 2, 3, and l, respectively. The cover panel lis provided with a sealing flap l4 defined by the score 6. A strip ofglue I5 is applied to the undeiface of the sealing fiap M which in theerected position of the carton lies flatwise against front wall panel 4.The outer or free edge of the sealing flap it provides a sealing teartab 16 which lies fiatwise against the front wall panel :2 in theassembled position of the carton. i'wo parallel lines of perforations orslits ii are substantially parallel to the free edge of the tear orpeeling tab l5 and are near the score 8 along which the sealing flap Hiis folded to a position fiatwise against the front wall panel :3.

One way of assembling the carton comprises folding the bottom panel endflaps 12, the front panel A, and the rear panel 2 upwardly from thebottom panel 3, folding the front and rear wall end flaps i3 and i iinwardly and fastening them to each other, folding the cover panel endflaps ll! inwardly toward the box formed so that the lower edges of saidend flaps it are positioned directly over the spaces between theupstanding bottom panel end flaps l2 and the joined front and rear wallend flaps is and ii, folding the cover panel l downwardly, applying anadhesive to form a glue strip l5, and folding the sealing flap l4downwardly against the upper portion of the front wall panel 4. In amanufacturers variation of the assembly of the carton the tear tab it issecured first to the wall panel 6 whereupon the carton is shipped inllatwise condition. To open the carton the front and rear wall end flapsl3 and ii are disengaged and the tear tab it is grasped near one endthereof and pulled outwardly until the glue bond is broken, whereuponall portions of the carton may be readily opened and folded back intothe plane of the bottom panel, thereby exposing the contents. The cartonmay also he opened by lifting upwardly at the center of the tear tab it.With this method of opening the tear tab it is not detached.

The parallel lines of perforations are spaced apart a sufficientdistance to avoid the accidental breaking of the sealing flap i l bytwisting but are sufiiciently close to insure an easy release of thesealing flap is. With this arrangement the liner on the underface oi theflap 34 does not tear at the extremities of the lower line ofperforations and any tendency to tear is promptly arrested by the upperperforations, the ends of which slightly overlap the opposite ends ofthe lower perforations. Consequently, the liner on the inner face of thesealing flap M is completely severed by the staggered double row ofperforations and any tendency to tear beyond the upper line ofperforations is completely arrested.

Any tearing of the outer ply of the sealing flap [4 is arrested in asimilar manner by each of the forms of perforations illustrated inFigures 4, 5 and 6.

In the embodiment described the distance between the two parallel linesof slits may be varied. Generally, the greater the thickness of thematerial the closer the rows of slits may be placed together. The spacebetween the two rows is varied so as to allow for constant ease ofopening for all grades of material.

It is to be understood that the embodiments herein described areillustrative and not restrictive, and it is also to be understood thatthe invention may be susceptible of embodiment in other modified forms,and that all such modifications which are similar or equivalent heretocome equally within the scope of the claim next appeering.

What I claim is:

A carton comprisng foldably, integrally connected bottom, side and topwalls, the top and bottom walls having foldably connected, integral endflaps disposed right angularly inwardly in overlapping relation to formcarton end walls, the side walls each having foldably, integrallyconnected end locking tabs disposed in releasably locked relationshipand positioned against the outer face of the end flaps, the top wallhaving an integral sealing flap foldably connected to the front sidemargin thereof and disposed downwardly, flatwise against the upperportion of the outer f ce oi the adjacent side wall, the sealing flapsecured to the adjacent side wall only by a longitudinal glue strip ofsubstantially less width than the sealing and positioned parallel tospaced considerably inwardly from its free outer side edge thus leavinga free unsecured longitudinally extending marginal portion of thesealing nap, means for arresting tearing and peeling of the exposedliner ply on the underface of the sealin flap when the glue bond betweensealing flap and the adjacent side wall is broken, said means comprisinga row of closely spaced together, overlapping slits severing the exposedliner ply on the underface of the sealing flap, the row of slits beingpositioned closely adjacent and substantially parallel to thelongitudinal glue strip, unsecured to the adjacent side wall, and spacedoutwardly from the foldable connection between the glue strip and thetop wall, whereby the said marginal portion of the sealing nap may bereadily gripped with the fingers to enable the same to be pulled freefrom the adjacent side wall.

References sited in the file of this patent UNITED STATES PATENTS NumberName Date 1,961,375 McAleer June 5, 1934 2,181,837 Snyder et al Nov. 28,1939 2,210,872 Ariail Aug. 13, 1940 2,218,599 Goodyear Oct. 22, 19402,285,542 Tasker June 9, 1942 2,535,531 Heywood Dec. 26, 1950 2,557,914Miller June 19, 1951

